Minimally-invasive catheter-based interventions have revolutionized our treatment of cardiovascular disease. X-ray techniques have been the established method for imaging coronary and vascular disease and guiding interventional therapeutic devices. X-ray, however, does not directly visualize the diseased atherosclerotic tissue, limiting more advanced vascular interventions. Magnetic resonance imaging (MRI), by comparison, provides excellent tissue contrast and can image both the vessel lumen and the vessel wall without relying on contrast agents. At Stanford we have been actively developing real-time interactive MR imaging systems for diagnostic cardiac imaging, and for the guidance of interventional procedures. In this proposal we will significantly extend this work to the visualization and control of devices for vascular interventions, and the integration of these capabilities into a multi-functional interactive real-time interface. The major focus will be to develop a fully integrated MRI system for real-time vascular interventions and to optimize its capabilities in animal models for the treatment of chronic total occlusions.